Process of countersinking holes in metal



Patented Dec. 18, 192 8.

pours or rnpianh rorg s; INDIANA, AssrenoR' ro rears coarona'rron;

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PROCESS-E oounrnnsmxmeinonns IN-"METAL. f

Application filedDecember 19,1927. Serial No. 241,023.

This invention relates to a process of coun= 1 tersinking holes in metalplates.

The chief featureof the invention consists in forming thecountersunkportion oftheg the plate in the die with respect to the conihole priorto the formation of the hole itself,

and thereafter forming the hole Within the countersunk portion andto thedesired outline.

The full nature of the invention will be understood from theaccompanying drawings and thefollowing description and claim:

In the drawings Fig. 1 represents a plan view of a sheet of metal. Fig.2 is a central sectional view thereof. Fig. 3 is a top plan view of themetal after the countersinking.

has occurred. Fig. 4: is a central section through the countersunk plateshown in Fig.

countersunk portion 115, the conical projecting portion116 and the wall123 of the Band of the dies for securing the same. Fig. 5

is a top plan view of the plate with a counter the hole formedthereinand the dies for form-f ing the same. Fig. 7 is a view similar toFig. 5 and shows a square hole instead of a circular hole. Fig. 8 is aviewsimilar'toFig. 6 with the dies omitted. Fig. 9 is a view similar toFigs. 5 and 7 and is of a plate having a countersunk hexagonal hole.Fig. 10 is a view similar to Figs. 6 and 8 with the dies omitted. Fig.11 is a view similar to Fig. 8 andof a plate wherein the countersunkportion does not project from the opposite face but shows the wallsofthe hole flush with the face of the plate. Fig.12 is a view similar toFig. 10 and shows the flush arrangement of the plate with thecountersunk hole. Fig. 13 is a view similar to Fig. 6 of the plate withthe walls of the countersunk hole flush with the opposite face of theplate.

In the drawings, 10 indicates ametal plate which is placed between amale and female. I die, the female die 11 having a conical hole or irecess 12 therein and the male die 13 having a the metal therebetween iscaused to form a conical recess 15 in one face and a conical projection16 upon the opposite face of the plate. For all of the severalmodifications shown herein the foregoing constitute the first and commonstep;

The metal plate 10 is thereupon positioned in a perforate die having thefemale portion,

17 with" a conical seat 18-adapted to receive the conical projection 16and therebycenter cal recess 15; The die 17 has a flared open-' 1 ing 19extending therethrough through which the severed portion 20 of the metalplate is projected. The male head 21 has-a'cutting portion 22 of thedesired peripheral outline and the opening 23 is formed comp-lementarily thereto to receive the same.

As shown clearly in Figs. 5 and 6, the wall 23 of the opening is hereinshown circular and concentric, or' coaxial with j the countersunk.

portion15. n In Figs. '7 and 8 the blank 110 includes the opening whichherein is shown square.

Figs. 9 and 10 illustrate plate 210 having I the countersunkportion 215coaxial with the and having a wall 223 wall 123 square similar to thatshown in Figs. 7 and8,but herein the projection 116 is omitted and thisis obtained by grinding the projection 116 from the face so that thereis no projection upon the face opposite the countersunk face or byproviding a die, see

Fig. 6, which willnot have the recess 18 .8

therein, but which will be square shoul-,

dered, or suitably formed so that the pro jecting portion 16 will heremoved by the die head 22 in themeeting engagement of the 1 two dieportions. The removal of this projection may thus occur simultaneouslywith v the formation of the hole in the countersunk portion.

Fig. 12 is similar to Fig.10, but show'sthe plate having a flush faceopposite the coun-' tersunk portion. I F'ig. 13 is similar to Figs. 11and 12, of the flush face type but of the plate shown in Figs. 5 and 6.v

While the invention has been specifically described and illustrated asincluding a conia Y I cal countersunk portion, it is, of course, to

be understood that the countersinking ne'ces sarily may have a pyramidalor any other plate to form a conical recess in one face and desired.outline, and where the terminology a projection upon the opposite face,and 10 conical is employed in the claim the aforethereafter removing thecentral portion of said disclosure is to be considered as equivatherecessed portion of the plate and all of the lent in interpreting thescope of said claim. projected portion upon the o posite face.

The invention claimed is: a In Witness whereof, I have hereunto affixedThe process of counter-sinking holes "in my signature. metal plates,consisting of deforming the r a e V LOUIS G. WINKLER.

